Core B Pathology will provide services using histological, immunohistochemical, and immunofluorescence method on human neuroblastoma tissues and xenograft models for Project 1-3. Through this Core, services using confocal microscope will be available for analyzing immunofluorescence images. Core B also will utilize digital electron microscopy, when requested, on human and animal samples. Core leader will make a histopathology evaluation on human neuroblastoma cases according to the International Neuroblastoma Pathology Classification, and also provide the results of histology evaluation on bone marrow biopsies/aspirates from the patients for Project 4. During this project period, Core B pathology will establish Biorepository system and TMA for the high-risk human neuroblastoma tumor samples.